Effects Of nano-CuO Research Articles

Effect of Nano-CuO and 2-Mercaptobenzothiazole on the Tribological Properties of Ultra-High Molecular Weight Polyethylene

In this study, the tribological properties of nanocomposites based on ultra-high molecular weight polyethylene (UHMWPE) filled with nano-CuO and 2-mercaptobenzothiazole (CuO/MBT) in mass ratios of 1:1 and 2:1 were investigated. In the supramolecular structure of UHMWPE nanocomposites, spherulites of several hundred micrometers in size are formed. The density of UHMWPE nanocomposites slightly increases relative to the pure polymer, reaching a maximum at 2 wt.% CuO/MBT in both ratios. The Shore D hardness and compressive stress of the UHMWPE nanocomposites showed an improvement of 5–6% and 23–35%, respectively. The wear resistance and coefficient of friction of UHMWPE nanocomposites were tested using a pin-on-disk configuration under dry friction conditions on #45 steel and on P320 sandpaper. It was shown that the wear rate of UHMWPE nanocomposites filled with 2 wt.% CuO/MBT decreased by ~3.2 times compared to the pure polymer, and the coefficient of friction remained at the level of the polymer matrix. Abrasive wear showed an improvement in UHMWPE nanocomposites filled with 1 wt.% CuO/MBT compared to the polymer matrix and other samples. The worn surfaces of the polymer composites after dry friction were examined by scanning electron microscopy and IR spectroscopy. The formation of secondary structures in the form of tribofilms that protect the material from wear was demonstrated. Due to this, the wear mechanism of UHMWPE nanocomposites is transformed from adhesive to fatigue wear. The developed materials, due to improved mechanical and tribological properties, can be used as parts in friction units of machines and equipment.

The Theoretical Ballistic Performance of Alumina Ceramics and the Effect of Nano Oxides Addition Using Finite Element Analysis

The present investigation has turned on the effect of nano CuO and TiO2 as a dopant on ballistic performance of sintered alumina armours and its results are simulated using finite element analysis. The model was constructed on armor-backing plate (Al6061-T6) assembly with a steel made core and copper made outer jacketed bullet at high velocity (820 m/s) by Ansys workbench. The depth of penetration of bullet drastically reduces to 36.17% due to addition of 2 wt% nano CuO with respect to pure alumina. The same optimized effect shown by 1 wt% nano TiO2 is about 40.42%. The residual velocity of bullet gradually decreases with time and there is more reduction of residual velocity of 38% and 56.82% at 140 μs by addition of 2 wt% nano CuO and 1 wt% nano TiO2 respectively with respect to pure alumina. The alumina armours with 1 wt% nano TiO2 addition showed the best ballistic performance as compared to nano CuO.

The effect of nano-CuO on mechanical, microstructural, and self-healing properties of clayey sandy soils

The effect of nano-CuO on mechanical, microstructural, and self-healing properties of clayey sandy soils

Effective Parameter of Nano-CuO Coating on CO Gas-Sensing Performance and Heat Transfer Efficiency

The high gas-sensing performance of semiconductors is mainly due to the high surface-to-volume ratio because it permits a large exposed surface area for gas detection. This paper presents an evaluation study for the effects of nano-CuO coating parameters on the CO gas-sensing performance. The effects on gas-sensing performance and heat transfer efficiency of CuO coating were evaluated by investigating the effects of coating parameters (concentration, temperature, and solution speed) on thickness, grain size, and porosity. The CuO nanoparticle coatings were synthesized using the oxidation method at various operating conditions. Coating characteristics were investigated using X-ray diffraction, energy dispersive X-ray Spectroscopy, field emission scanning electron microscopy, and electrical resistivity meter. The average coating thickness, grain size, and porosity were around 13 μm, 48 nm, and 30%, respectively. The thermal transfer and gas-sensing properties of CuO coating were evaluated according to the total surface area of the coating formed at various operating conditions. The gas-sensing and thermal transfer performance were obtained from the optimization of coating parameters based on the coating morphology to achieve the highest contact surface area. The coating’s surface area was increased by 350 times, which improved the heat transfer efficiency of 96.5%. The result shows that the coating thickness increased with the increase in solution concentration and decrease the temperature. The results also show that the sensitivity of the coating for CO gas was increased by 50% due to the reduction of coatings grain size.

Nano-Scale Copper Oxide: Preparation, Characterization and its Effect on the Thermal Behavior of Ammonium Perchlorate

A new generation of high energy materials depends on the use of Nano-particle oxides. Nano-scale copper oxide (nano-CuO) has large surface area and surface energy which is suitable for its application in the field of energetic materials. This manuscript reports a method for the synthesis of nano-CuO by a liquid-state reaction method. The prepared nano-CuO was characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD) to check the particles size, purity and morphology of the crystals. The effect of Nano-CuO on the thermal behavior of AP was tested by differential scanning calorimeter (DSC). The results proved that the average particle sizes of the nano-cuo particles are in the range of 10-20 nm. The thermal degradation rate of AP was increased by 23% in the presence of 1% nano-CuO and the heat release was increased by 51%. It was concluded that nano-CuO could have obvious effect on the burning behavior, performance and combustion characteristics of the solid rocket propellants.

Nano-CuO impairs spatial cognition associated with inhibiting hippocampal long-term potentiation via affecting glutamatergic neurotransmission in rats

Manufactured metal nanoparticles and their applications are continuously expanding because of their unique characteristics while their increasing use may predispose to potential health problems. Several studies have reported the adverse effects of copper oxide nanoparticles (nano-CuO) relative to ecotoxicity and cell toxicity, whereas little is known about the neurotoxicity of nano-CuO. The present study aimed to examine its effects on spatial cognition, hippocampal function, and the possible mechanisms. Male Wistar rats were used to establish an animal model, and nano-CuO was administered at a dose of 0.5 mg/kg/day for 2 weeks. The Morris water maze (MWM) test was employed to evaluate learning and memory. The long-term potentiation (LTP) from Schaffer collaterals to the hippocampal CA1 region, and the effects of nano-CuO on synases were recorded in the hippocampal CA1 neurons of rats. MWM test showed that learning and memory abilities were impaired significantly by nano-CuO ( p < 0.05). The LTP test demonstrated that the field excitatory postsynaptic potential (fEPSP) slopes were significantly lower in nano-CuO-treated groups compared with the control group ( p < 0.01). Furthermore, the data of whole-cell patch-clamp experiments showed that nano-CuO markedly depressed the frequencies of both spontaneous excitatory postsynaptic currents (sEPSCs) and miniature EPSCs (mEPSCs), indicating an effect of nano-CuO on inhibiting the release frequency of glutamate presynapticly ( p < 0.01). Meanwhile, the amplitudes of both sEPSC and mEPSC were significantly reduced in nano-CuO-treated animals, which suggested that the effect of nano-CuO modulates postsynaptic receptor kinetics ( p < 0.01). Paired pulse facilitation (PPF) ( p < 0.05) and the expression of NR2A, but not NR2B, of N-methyl-d-aspartate (NMDA) subunits ( p < 0.05), were decreased significantly. In conclusion, nano-CuO impaired glutamate transmission presynapticly and postsynapticly, which may contribute importantly to diminished LTP and other induced cognitive deficits.

Effect of Nano-CuO on Engineering and Microstructure Properties of Fibre-Reinforced Mortars Incorporating Metakaolin: Experimental and Numerical Studies.

In this study, the effects of nano-CuO (NC) on engineering properties of fibre-reinforced mortars incorporating metakaolin (MK) were investigated. The effects of polypropylene fibre (PP) were also examined. A total of twenty-six mixtures were prepared. The experimental results were compared with numerical results obtained by adaptive neuro-fuzzy inference system (ANFIS) and Primal Estimated sub-GrAdient Solver for SVM (Pegasos) algorithm. Scanning Electron Microscope (SEM) was also employed to investigate the microstructure of the cement matrix. The mechanical test results showed that both compressive and flexural strengths of cement mortars decreased with the increase of MK content, however the strength values increased significantly with increasing NC content in the mixture. The water absorption of samples decreased remarkably with increasing NC particles in the mixture. When PP fibres were added, the strengths of cement mortars were further enhanced accompanied with lower water absorption values. The addition of 2 wt % and 3 wt % nanoparticles in cement mortar led to a positive contribution to strength and resistance to water absorption. Mixture of PP-MK10NC3 indicated the best results for both compressive and flexural strengths at 28 and 90 days. SEM images illustrated that the morphology of cement matrix became more porous with increasing MK content, but the porosity reduced with the inclusion of NC. In addition, it is evident from the SEM images that more cement hydration products adhered onto the surface of fibres, which would improve the fibre–matrix interface. The numerical results obtained by ANFIS and Pegasos were close to the experimental results. The value of R2 obtained for each data set (validate, test and train) was higher than 0.90 and the values of mean absolute percentage error (MAPE) and the relative root mean squared error (PRMSE) were near zero. The ANFIS and Pegasos models can be used to predict the mechanical properties and water absorptions of fibre-reinforced mortars with MK and NC.

RETRACTED: Effect of nano-CuO and fly ash on the properties of self-compacting mortar

Abstract This paper presents the fresh and hardened properties of self-compacting mortar (SCM) incorporating nano-CuO (NC) and fly ash (FA). CuO nanoparticles at the rates of 1%, 2%, 3% and 4%, and low-calcium fly ash at the rates of 20%, 25%, and 30% of the binder by weight were considered. Mini slump flow diameter and mini V-funnel flow time tests were conducted to determine the rheological properties of SCMs incorporating fly ash and nano-CuO. Compressive strength was determined at the ages of 7 days as an early age, 28 days as the standard age and 90 days as a late age. Water absorption, electrical resistivity and rapid chloride permeability tests (RCPT) were also performed to determine the durability properties. The results showed significant improvement in the mechanical properties of the samples incorporating the replacement of cement with a combination of 3% CuO nanoparticles and 25% FA. Chloride permeability and electrical resistivity of the FA blended mixtures improved with the increase of nano-CuO content up to 4%. The SEM micrographs indicated more packed pore structure of the SCMs containing nanoparticles which could lead to increasing the strength and durability of specimens.

Effect of Nano-CuO on Luminous Intensity of Pyrotechnics Composite Containing KClO&lt;sub&gt;4&lt;/sub&gt; and Al

Nano-CuO had been successfully synthesized by using direct precipitation method. The prepared sample was characterized by XRD. The luminous intensities of pyrotechnics composite containing KClO4, Mg and nano-CuO were measured. The catalysis of CuO nanocrystal on KClO4 was investigated by thermal analysis instrument. The results show that the average size of nano-CuO is 19 nm and has spherical-shape. When nano-CuO is added into the pyrotechnics composites containing KClO4 and Al, it can improve the igniting and burning performance. The luminous intensity of trinary pyrotechnics composite is also greatly increased. On the other hand, nano-CuO can make thermal decomposition temperature of KClO4 to decrease 97.7 °C, the decalescence amount also reduced to 79.07 J/g. It is obviously that nano-CuO has strong catalysis to KClO4 thermal decomposition. The conclusion is consistent with the measure results of luminous intensity.

Nanosized copper oxide induces apoptosis through oxidative stress in podocytes

Nanosized copper oxide (nano-CuO) has been widely used in many fields. Recent studies have shown that nano-CuO has toxic effects on various organs, but the effects of nano-CuO on kidney remain unclear. The aim of this study was to assess whether nano-CuO can induce the apoptosis of podocytes. The result of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay indicated that nano-CuO decreased podocyte viability in a concentration-dependent and time-dependent manner. The apoptotic assay by flow cytometry showed that nano-CuO induced podocyte apoptosis significantly. Meanwhile, the result of flow cytometric assay gave a clear indication that nano-CuO increased reactive oxygen species (ROS) level. The measurement of superoxide dismutase (SOD) and malondialdehyde (MDA) showed that nano-CuO decreased SOD and increased MDA levels in podocytes. These results may provide basic information for the safe application of nano-CuO in the future.

A Synergistic Effect of Graphite and Nano-CuO on the Tribological Behavior of Polyimide Composites

Polyimide (PI) composites modified with nano-CuO and graphite were prepared by means of a hot press molding technique. The effects of nano-CuO and graphite on the tribological properties of the composites were studied using a block-on-ring arrangement. The results revealed that the incorporation of graphite alone improved the friction-reducing and anti-wear abilities of the PI composites, whereas incorporation of nano-CuO alone deteriorated the wear resistance of the PI composite owing to its abrasive effect. A synergistic effect was found for the combination of nano-CuO and graphite, which leads to the best tribological properties. The results showed that the filled PI composites exhibited worse tribological properties under higher load and sliding speed, and showed better friction and wear behavior under oil lubrication and worse tribological properties under water lubrication.